The inventive concept relates to an analog-digital converter, and more particularly, to an analog-digital converter having multiple feedback, and a communication device including the analog-digital converter.
An analog-digital converter is an apparatus that converts an analog input signal to a digital output signal. For example, a wireless communication system uses the analog-digital converter to convert a received radio frequency (RF) signal to an analog baseband signal and generate a digital output signal from the analog baseband signal. Types of analog-digital converters include a flash-type analog-digital converter operating at a Nyquist rate, a successive approximation register (SAR) type analog-digital converter, and a delta sigma analog-digital converter operating at an oversampling frequency higher than Nyquist rate, which are used in application fields according to their characteristics.